Dental practitioners have been aware for years that the repeated insertion of the dental hand piece into the mouths of several different patients without sterilization of the hand piece between such uses can bring about the spread of contagious diseases. Such contagious or communicable diseases are borne in or on the body fluids and/or tissues which become attached to the exterior surfaces of the hand piece. More recently the spread of the Hepatitus virus and the Acquired Immune Deficiency virus have caused great concern for dental practitioners, not only for their patients, but also for their own health and well-being.
Both the Hepatitus virus and the Acquired Immune Deficiency virus are carried in or on body fluids and/or tissues. In the environment in which dental practitioners work, i.e. inside the mouth, body fluids such as saliva, blood, etc. and the tissues comprising the gum and portions of the teeth, the pulp and root, may potentially transmit the virus through contact. The process of cleaning and/or repairing teeth by filling caries or performing a root canal procedure requires the drilling of the teeth and the subsequent scattering of tissue particles and body fluids about the mouth. Some of those particles and/or fluids become attached to adhere to the dental hand piece. Cleaning and sterilizing the hand piece between patients has been a serious problem for dental practitioners because of its construction.
The straight pulley driven dental hand piece was attached to the drive unit by a series of pulleys comprising several gears and belts. It was extremely difficult to remove the hand piece for sterilization even at the conclusion of the day's work. Dental practitioners were reduced to wiping the hand piece with solutions to disinfect the exterior and any inner surfaces which were reachable. These procedures were not extremely effective. If the hand piece were removed, it could be placed in an auto-clave unit for sterilization by subjecting it to extremely high temperatures. However, upon remounting, the hand piece required lubrication or its functioning over the wide range of speeds would be severely hampered if not totally impaired. Most dental practitioners relied on the disinfectant solutions rather than chance the loss of the rather expensive hand piece by attempting removal, cleaning, remounting and lubrication.
Even the newer dental hand pieces capable of extremely high speeds are difficult to clean and sterilize. In addition to the problem of removal and reattachment, the relatively small sized dental hand pieces have angled-heads containing high speed air-driven turbines for providing the motive force for the various dental tools. The air-driven turbines are extemely sensitive to the corroding effects of an auto-clave unit; high temperatures, chemical agents and the resulting moisture during cooling. Lubrication of the miniature mechanisms may not be sufficient to return the high speed air-driven turbine to its fully operational capabilities.
Early attempts at creating protective coverings for the dental hand piece were relatively unsuccessful. Some examples of protective coverings to provide better sanitary conditions in the dental practitioner's office are the devices disclosed in U.S. Pat. Nos. 949,273 (Hinrichsen), 1,162,941 (Martin, et al.), 1,342,968 (Moolten), 1,470,162 (Gruss), 1,691,823 (Ogilvie), 1,742,061 (Curry) and 2,041,077 (Lininger). The Hinrichsen, Gruss and Lininger patents disclose protective coverings made of rigid materials, such as metals, of either one or two piece construction, which can be placed over the hand piece and removed for cleaning. The Martin, et al., Moolten, Ogilvie and Curry patents disclose attempts to incorporate flexible materials and/or thinner and lighter materials into the coverings to alleviate the problems of lack of manipulative control over the hand piece with the cover in place and the lack of tight fitting joints which permitted the fluids and tissue materials to get under the protective coverings.
Later attempts to improve and overcome the limitations of earlier versions of protective coverings brought into wider use elastic materials. Some examples of protective coverings using and/or incorporating elastic-type materials are disclosed in U.S. Pat. Nos. 1,485,963 (Curry), and 2,073,137 (Bimrose). These devices partially eliminated the problem of tight fitting joints and remedied, to a limited extent, the problem of manipulative control.
However, a new problem arose with the use of the tight fitting elastic materials. Ease of installation and removal was lacking as was the ability to change a bur or other dental tool without removal of the covering entirely. Further the elastic material most commonly used was natural rubber which, when wet, became slippery and difficult to hold. Although these elastic protective coverings may have solved some of the problems encountered by dental practitioners with the rigid coverings, they were not widely accepted and are not believed to be in use today.
Compared to the foregoing attempts at solving the problems of providing a workable protective covering a more recent attempt appears to be nothing more than using newer materials in the old way. U.S. Pat. No. 4,266,935 (Hoppe) discloses a protective sleeve of elastic material for pulling over the hand piece. The single piece construction appears to provide for the variety of angled hand pieces in use today but does not take into account the motive force for driving the drill or other dental tool. Modern dental hand pieces are driven by using compressed air forced through a miniature turbine. The turbine is attached to a chuck which is adaptable for holding a variety of dental tools of varying shaft length and diameter. The air, once used to power the turbine, requires an exhaust port. Without provision for the release of air through an exhaust the turbine will stop resulting in the loss of motive force to the dental tool.
This recent development of using a single piece construction to alleviate earlier problems in protective coverings gives rise to additional problems. The lack of an air exhaust port makes this device usable only on earlier models of the dental hand piece which still use a pulley drive. There still exists the problem of removing the protective sheath entirely to change a bur or other dental tool. It is also questionable whether a pre-formed sheath as disclosed in Hoppe will be capable of being installed on the hand piece with the bur or other dental tool in place without ripping or tearing, or damaging the dental tool.
In recent years dental practitioners have become increasingly aware of the rapid spread of communicable diseases through body fluids and tissues such as may be dislodged and/or become attached to the dental hand piece during its use in the mouth of a patient. In fact, dental practitioners have been cautioned to protect themselves from infection by using sterile gloves and masks and to use protective glasses when practicing dentistry on their patients. Very recently the rapid spread of the Hepatitus virus and the Acquired Immune Deficiency virus has caused significant concern among dental practitioners. The American Dental Association and other professional organizations have strongly urged that dental practitioners take additional steps to decrease the chance of spreading the disease through the use of non-sterile implements.
It is therefore an object of the present invention to provide a sterile protective covering or shield for the dental hand piece to significantly reduce o prevent the spread of contagious, communicable diseases.
It is a further object of the present invention to provide such a shield which is disposable after a single use and which is easily applied and removed so that it will have wide-spread acceptance in the dental professions.
It is another object of the present invention to provide such a shield which is highly elastic and stretchable, yet tear resistant, and which is capable of covering the entirety of a variety of dental hand pieces.
It is also an object of the present invention to provide such a shield with allows access to the releasable securing mechanism of each hand piece so that a dental practitioner or other dental professional need not remove the shield in order to change or adjust the dental tool.
It is also an object of the present invention to provide a shield which can accomodate the newer air-driven hand pieces which require an air exhaust port and to provide for hand piece incorporated lights and water spray attachments.
Other objects will appear hereinafter.